One of the biggest causes of boiler problems is incorrectly sized gas pipework.
When a new boiler is fitted, the output is often higher than the old one — but the gas pipe is left the same. That’s a recipe for trouble.
Undersized pipes mean:
* Reduced boiler performance
* Lockouts and ignition faults
* Poor combustion
* Increased risk of carbon monoxide
Your boiler can only work as well as the gas supply feeding it.

📲 Pipe Sizing Made Simple
The Mr Combi Pipe Sizing App takes the guesswork out of gas calculations. In seconds you can:
1. Select the gas type
2. Enter the appliance heat input
3. Enter the pipe length
4. Choose the number of high or low-loss fittings (clear guidance is built in)
5. Select the pipe material
6. Tap Calculate

✅ Instant Results You Can Trust
The app instantly shows:
* Total equivalent pipe length
* Minimum required pipe diameter (metric)
* Pressure drop for that section of pipe
So you know the pipe is safe, compliant and big enough to supply the boiler at full load.
Important: Designed for the UK market, the app uses metric pipe sizes in line with UK standards.

🚀 Download Now
Stop guessing. Stop undersizing.
👉 Download the Mr Combi Pipe Sizing App today and make every installation safer, more efficient and fully compliant.